Textile bobbin

ABSTRACT

A WOODEN BOBBIN IS DISCLOSED HAVING SYNTHETIC RESINS OF THE ACRYLIC GROUP IMPREGNATED ENTIRELY WITHIN THE DIMENSIONS OF THE BOBBIN TO PROVIDE A SURFACE WHICH SHALL BE PHYSICALLY AND CHEMICALLY RESISTANT TO A VARIETY OF MAN-MADE YARNS.

United States Patent 01 3,577,271 Patented May 4, 1971 3,577,271 TEXTILE BOBBIN Roger Bliven, Hopedale, Frank L. Allen, Jr., Hudson, and John R. Davis, Uxbridge, Mass., assignors to John Donald Marshall and Horace L. Bomar, Trustees of The Carolina Patent Development Trust No Drawing. Continuation of application Ser. No. 607,626, Jan. 6, 1967. This application June 6, 1969, Ser. No. 858,552

Int. Cl. B44d 1/28 US. Cl. 117148 1 Claim ABSTRACT OF THE DISCLOSURE A wooden bobbin is disclosed ha ving synthetic resins of the acrylic group impregnated entirely within the dimensions of the bobbin to provide a surface which shall be physically and chemically resistant to a variety of Man-Made yarns.

This application is a continuation-in-part of application Ser. No. 607,626, filed on Jan. 6, 1967, now abandoned.

BACKGROUND OF THE INVENTION (1) The invention pertains to improvements in the physical properties of wooden textile bobbins by impregnation through immersion in modified acrylic resins.

(2) The impregnation of textile bobbins to produce a bobbin surface of greatly increased hardness and resistance to chemical reaction has been disclosed in recent US. Pats. Nos. 3,029,159 and 3,243,140, both issued to Roger Bliven et al. In both instances the resulting bobbin surfaces, while an improvement over previously known finishes, have not been completely satisfactory. The impregnant in both cases was not received within the cellular structure of the bobbin without slightly changing the surface dimensions of the bobbin. Sufficient raising of the wood grain was noted to require further operations of wire wooling and burnishing or tumbling to smooth the surfaces for actual use. Complete resistance to chemical reaction to certain yarns Was also not achieved. The instant invention provides a bobbin whose surface acquires the hardened characteristics of the cured impregnant without appreciable change in its outer dimensions. The surface remains as smooth as when originally turned While becoming increasingly resistant to the action of those compact, interlaced yarns which previously have been difficult to weave.

SUMMARY Problems have been encountered in weaving of certain multifilament yarns having very low or zero twist, and particularly those yarns known as compact, interlaced yarns as disclosed in the US. Pat. No. 2,985,995. Such yarns are manufactured by E. I. du Pont de Nemours & Co. from nylon and Dacron and sold as Rotoset yarns.

When such yarns are used as filling in the weaving process and wound upon wooden bobbins with any known surface finish, there invariably appears over the entire surface, after a short period of use, a tacky, rubbery, mo-

bile jell. This undesirable material has formed on bobbins with any of the conventional surface coatings such as lacquer, paint, baked or unbaked enamel, varnish, etc., or whether the wood was impregnated with certain resins as disclosed in the US. Pat. No. 3,029,159, or Whether the bobbin has been impregnated and then surface coated.

The instant invention provides a filling bobbin whose surface is not affected adversely by the compact, interlaced yarns mentioned above and whose surface is highly resistant to pressure and other physical abuse.

In impregnated bobbins such as those disclosed in the patents cited above, the various resins have raised the wood grain to such an extent that smoothing operations were required to prepare the bobbins for use. In the present invention smoothing steps are not necessary as the impregnant is received wholly within the desired external measurements of the finished bobbin. The surface in addition provides minimal back tension to those diflicult 10w denier, flat filament yarns such as nylon.

It is a general object of the invention to devise an im proved filling bobbin which shall be chemically and physically resistant to the adverse effects of compact, interlaced yarns previously encountered.

It is another object of the invention to devise an impregnated wooden bobbin having a smooth hardened surface resistant to abrasion, denting and crushing without the necessity for further finishing operations.

It is a further object of the invention to devise an impregnated wooden bobbin capable of being produced in quantity with a marked reduction in rejection due to runout or crooked bobbins.

These and other objects of the invention will become apparent as further details are disclosed.

In the instant invention the above objects have been achieved and the disadvantages noted in bobbins of the prior art have been overcome. With bobbins impregnated with the acrylic resins and in the manner specified below, they are found to withstand long periods of continual use with complete resistance to the damaging effects of compact, interlaced yarns and general handling.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention generally comprises wooden bobbins dried to a relatively low degree, preferably below about 7% by weight of moisture, then impregnated with a resin including an acrylic monomer such as methylmethacrylate modified with a multifunctional acrylic monomer. Polymerization is then initiated with heat and a free radical type catalyst such as benzoyl peroxide, azobisisobutyronitrile, 2,5-dimethyl-2,5-di(t-butylperoxy) hexane, etc. The multifunctional acrylic monomer may be selected from the group including: Trimethylolpropanetrimethacrylate, ethyleneglycoldimethacrylate, triethyleneglycoldimethacrylate, tetraethyleneglycoldimethacrylate, polyetheleneglycoldimethacrylate, 1,3 butyleneglycoldimethacrylate, etc.

EXAMPLE I An impregnation formula was prepared by mixing the following:

Parts by weight Methylmethacrylate-monomer 30 1,3-butyleneglycoldimethacrylate 70 Benzoyl peroxide 1 The viscosity of this mixture was .005 poise at 25 C.

Bobbins were dried 16 hours at 275 F. to less than 7% by weight of moisture, and preferably to about 3% or less by Weight of moisture. They were then loaded into a pressure type vessel from which air was evacuated to establish a vacuum of between 25 and 28 inches of mercury and maintained for 15 minutes. The above mixture was admitted to the vessel to completely cover the bobbins for 15 minutes which were then drained for 30 minutes. They Were cured while tumbling for 1 /2 hours at 180 F. to 285 F.

The impregnated bobbins contained 36% by weight of resin and had a Barcol hardness (Ser. No. 4,718) between 52 and 57. After a 24-hour moisture test, the bobbins disclosed a weight gain of 14.8% with dimensional gains of 2.6% perpendicular to the grain and 4.8% parallel to the grain. When examined for straightness they averaged only 4% rejects when tested for an allowable runout of .014".

These bobbins were placed in service upon looms weaving Rotoset filling yarn with automatic loomwinders to provide continual reuse of each bobbin. They were found to be unaffected by the filling yarn after months with no rubbery, tacky jell appearing upon the bobbin surfaces. Previously this undesirable condition resulted after a short period of time and required hand cleaning operations before further use was possible.

EXAMPLE II A second impregnation formula was prepared as follows Parts by weight Methylmethacrylate monomer 30 Trimethylolpropanetrimethacrylate 70 Benzoyl peroxide 1 These bobbins were impregnated and cured in the same manner as those in Example 1 with the viscosity of the mixture being .005 poise at 25 C. The cured bobbins contained 37% by weight of resin and had a Barcol hardness (Ser. No. 4,718) between 53 and 56. After a 24-hour moisture test, they had a weight gain of 12.0% with dimensional gains of 2.5% perpendicular to the grain and 4.0% parallel to the grain. A straightness examination showed only 4.3% rejects with an allowable runout of .014".

EXAMPLE 111 Parts by weight Methylmethacrylate monomer 30 Ethyleneglycoldimethacrylate 70 Benzoyl peroxide 1 Bobbins were impregnated and cured as in Example I in a mixture having viscosity of .005 poise at 25 C. When cured the bobbins contained 35% by weight of resin and had a Barcol hardness (Ser. No. 4,718) between 51 and 55. After a 24-hour moisture test, they had a weight gain of 14.3% with dimensional gains of 2.9% perpendicnlar to the grain and 5.8% parallel to the grain. There were 10.2% rejects when tested to runout below .014".

EXAMPLE IV Parts by Weight Methylmethacrylate monomer 74.5

Trimethylolpropanetrimethacrylate 24.5

Benzoyl peroxide 1.0

Bobbins were impregnated as in Example I in the above mixture having viscosity of .005 poise at 25 C. Curing was effected while tumbling at a temperature of 205 F. for 1 /2 hours. The cured bobbins contained 34% resin by weight and had a Barcol hardness ('Ser. No. 4,718) between 50 and 55. After a 24-hour moisture test, they had a weight gain of 15.1% with dimensional gains of 2.6% perpendicular to the grain and 4.6% parallel to the grain. The rejects due to runout in excess of .014" were 5.5%.

EXAMPLE V affected by compact, interlaced yarns during extended periods of repeated usage. The bobbin surface provided by impregnating with an acrylic monomer modified with a multifunctional acrylic monomer and initiating polymerization with heat and a free radical type catalyst has proven more chemically resistant to Rotoset type yarns and in addition more resistant to abrasion and damage by physical contacts. The bobbins resulting from the instant invention define better dimensional stability than previously known impregnated bobbins and offer benefits from fewer rejects and in requiring fewer and easier corrective operations during periods of use. The units of the formulations set forth herein are obtainable in the commercial market and ofier savings in purchase costs over previously used impregnating resins.

With use of the impregnating resins of this invention, bobbins do not require predrying or curing in a dry atmosphere in order to reach full hardness as has been required with previously known polyester and epoxy impregnated bobbins. It is noted, however, that predrying of the bobbins produces fewer rejects by reason of excessive runout. To obtain the advantages resulting from the instant invention, the resin content of the impregnated bobbins should be at least 10% by weight and preferably in excess of 25% by weight.

While one embodiment and modifications of the invention have been discolsed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but s intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claim.

We claim:

1. A wooden textile bobbin, the wood of which has been impregnated with a thermoset acrylic resin, the thermoset acrylic resin formed in situ and consisting of methylmethacrylate which is crosslinked with from about 25 to of a multifunctional acrylic monomer by a free radical type polymerizing catalyst wherein the mu tifunctional acrylic monomer is a member selected from the group consisting of trimethylolpropane trimethacrylate, ethyleneglycol dimethacrylate, triethyleneglycol dimethacrylate, tetraethyleneglycol dimethacrylate, tolyethyleneglycol dimethacrylate, 1,3-butyleneglycol dimethacrylate, the impregnated bobbin having dimensions substantially identical to those of the bobbin prior to impregnation and a resin content of at least 10% by weight, the impregnated bobbin being resistant to the solvent action associated with-the finish on compact, interlaced yarns.

References Cited UNITED STATES PATENTS 2,996,469 8/ 1961 Cole. 3,029,159 4/1962 Bliven. 3 ,03 7,955 6/ 1962 Carman. 3,083,118 3/ 1963 Bridgeford. 3,169,079 2/ 1965 Ferington. 3 ,240,619 3/ 1966 Winchester. 3,243,140 3/1966 Bliven.

WILLIAM D. MARTIN, Primary Examiner W. R. TRENOR, Assistant Examiner US. Cl. X.R.

my UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 577 271 Dated May 4 1971 Inventor(s) ROGER BLIVEN et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Change the assignee to North American Rockwell Corporation Column 4, line 30, change "5" to is Signed and sealed this 7th day of December 1 971 (SEAL) Attest:

EDWARD MEETCHERJR. ROBERT GO I'TSCHALK Attesting Officer Acting Commissioner of Patents 

